This invention consists of a quick fastening device for wristwatches geared towards quickly locking each end of a watchband to the watch case.
The invention is particularly beneficial to the watch-making industry.
In the industry, there are actually many quick-change systems that can fasten a watchband rapidly to the watch case to give the watchband an interchangeability feature.
Most known devices use essentially the same operating principle. Schematically, this consists first of attaching together two linking elements to the watchband and the watch case respectively. Then the linking element forming the casing with the locking mechanism should be at least partially blocked to secure the attachment made previously.
The disadvantage of these types of quick-change systems, however, is that they are not esthetically appealing when the locking mechanism is small since its presence inevitably unbalances the watch""s otherwise balanced appearance. The reduced size of the various parts used for fastening also makes them unreliable.
When the locking mechanism is of a similar size to that of the watch, other problems arise; namely, that of integrating the locking mechanism to the watch case. In fact, such an adaptation requires subsequent structural and/or formal modifications to the width of the watch, thereby increasing its selling price significantly. This configuration may also be detrimental to the watch""s overall look since the presence of a large locking mechanism greatly affects the esthetics of the device and can limit the variations in form. Furthermore, adapting such a quick fastening device to a pre-existing watch would be difficult. In fact, the reverse approach is preferable, that is, to design the watch in view of the fastening system that is to be applied.
In addition to these major inconveniences, the fastening devices previously mentioned are often deemed impractical to implement, thereby making them much less appealing to the clients for whom they are designed. These devices rarely offer both speed and reliability because one feature is always achieved systematically at the cost of the other.
Furthermore, the technical problem to be resolved by this invention is proposing a quick fastening device, geared towards attaching the end of a watchband to the watch case, in which the fastening device is equipped with a linking element attached to the watchband and a second linking element attached to the watch case, where the two linking elements can be secured by fitting them together. This would avoid the problems associated with the current techniques by offering quick action and reliability while being fully adaptable, reasonably priced, and more esthetically appealing.
With this invention, the solution to the technical problem posed consists of assembling one of the linking elements in an adjustable fashion onto the element to which it is attached, in a place between a designated xe2x80x9copenxe2x80x9d position and a designated xe2x80x9cclosedxe2x80x9d position. The linking elements can be assembled freely in relation to each other and solidly by attaching them into each other.
In the xe2x80x9copenxe2x80x9d position, the two linking elements are independent of each other; that is, they can be engaged or disengaged freely in at least one direction. In the xe2x80x9cclosedxe2x80x9d position, however, and assuming that they were previously assembled through a process of joining the elements one into the other, the elements are permanently linked since each direction is conveniently locked.
The linking element""s mobility is in any direction, insofar as an xe2x80x9copenxe2x80x9d and xe2x80x9cclosedxe2x80x9d position exist, as previously defined. Furthermore, the adjustable linking element may also be moved by a sideways motion and a rotating motion, or through a combined, more or less complex motion.
The adjustable linking element can be assembled conveniently on any of the parts to be assembled. Moreover, the term xe2x80x9celementxe2x80x9d throughout this text designates either the watch case or the watchband, depending on whether the adjustable linking element is attached to the watch case or watchband.
One of the characteristic features of this invention is that the adjustable linking element constitutes the female part of the attachment in the assembly of the two linking elements, through at least a partial penetration. It is thus equipped with at least one casing that can accommodate a protuberance of an essentially complementary form, and which is assembled onto the other linking element that constitutes the male part. The specific nature of the linking element, combined with its mobility in relation to the element to which it is attached, allows easy definition of at least one xe2x80x9copenxe2x80x9d and one xe2x80x9cclosedxe2x80x9d position, in which each respective female part casing would be free to be blocked by a portion of the surface of the male element in question.
Although the linking element is mobile in any type of motion, the same does not hold true for the lateral direction of movement. Moreover, based on another characteristic feature of the invention, the linking element""s mobility is essentially perpendicular to the plane of the element to which the adjustable linking element is attached.
This configuration offers maximal resistance to mechanical stresses exerted between the watch case and watchband during a watch""s normal use. In other words, we are referring here to tensile forces. The goal is evidently to prevent any unnecessary movement of the adjustable linking element and thus avoid any risk of sudden disengagement. Making systematical provisions for locking devices to secure the adjustable linking element in a xe2x80x9cclosedxe2x80x9d position is thus unnecessary.
Due to its essentially transversal movement, in relation to the direction in which most of the mechanical stresses are exerted between the watch case and watchband, the adjustable linking element, in fact, effectively withstands all forces that can propel it into an open position, similar to disengagement. In this invention, the adjustable linking element shifts in a direction where the mechanical stresses are the weakest and even virtually non-existent, under normal conditions of use.
Based on a current manufacturing method, currently adopted for the invention, the linking elements can be attached by fitting them together, essentially in a direction perpendicular to the line along which the linking element is assembled while allowing lateral movement. The linking elements"" direction of engagement and disengagement is essentially oriented in a parallel fashion to the line along which most of the mechanical stresses are exerted between the watch case and watchband.
Furthermore, the fastening device can naturally withstand the tensile stress exerted between the watch case and watchband since the linking elements can be attached conveniently by fitting them together along the direction of engagement that corresponds to a corresponding disengagement of the watch case from the watchband.
Lastly, since the linking elements direction of engagement and disengagement, when in a xe2x80x9cclosedxe2x80x9d position, is essentially perpendicular to the surface portion of the element that is in contact with the adjustable linking element, any accidental disengagement of the said linking elements would thus appear impossible. In fact, the surface portion of the supporting element forms an actual stop that can prevent access to the various casings on the adjustable linking element, and which are geared towards accommodating the male parts of the other linking element. In fact, the disengagement of the linking elements is totally controlled by the position of the adjustable linking element in relation to the supporting element to which it is attached.
The advantage to this invention, as defined, is its simple design since it does not require any specific locking device to secure the linking elements together, thus allowing the band to be quickly fastened to the watch. In this case, the locking function is carried out conveniently by the surface portion of the watch case, towards which the adjustable linking element is forced to move and/or position itself, once it is in a xe2x80x9cclosedxe2x80x9d position. This simple concept evidently results in increased reliability, quick action and a reasonable selling price.
Based on another manufacturing method for the invention, the linking elements can be attached essentially parallel to the direction in which the linking element is assembled, and in an adjustable fashion. Thus, the directions of engagement and disengagement of the adjustable linking elements are conveniently oriented and practically perpendicular to the direction along which most of the mechanical stresses are exerted between the watch case and watchband. In this way, the fastening device can naturally and effectively withstand the tensile stress, and eventually the pressure, exerted between the watch case and watchband.
However, with this configuration, making provisions for specific devices to secure the linking elements is essential. In fact, the securing function can no longer be carried out by the surface portion of the element to which the linking element is assembled while allowing lateral movement, as in the first manufacturing method. In this case, the surface portion in question, as well as the direction of engagement and disengagement, are essentially parallel, which prevents the surface portion from acting as a stop.
Moreover, the second manufacturing method of the invention ensures that the element supporting the adjustable linking element is equipped with at least one component creating a stop, and cooperating by making contact with the adjustable linking element when it is in the xe2x80x9cclosedxe2x80x9d position. The component creating the stop extends essentially perpendicular to the direction of engagement and disengagement of the linking elements.
Regardless of the manufacturing method used, and regardless of the fact that this may not be essential, the quick fastening device, which is the object of this invention, can be equipped with locking devices that can maintain the adjustable linking element in the xe2x80x9cclosedxe2x80x9d position. The purpose of this additional safety feature is to make the fastening device even more reliable.